# CVE-2026-53501: thumbor: Thumbor is an open-source photo thumbnail service by globo.com

CVE-2026-53501 is fixed in thumbor on 1 platform by DEBIAN-CVE-2026-53501 (version 7.8.0-1), released August 1, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-53501
- Priority: High
- CVSS: 8.2 (high)
- EPSS: 0.0035
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 31, 2026

## Description

Thumbor is an open-source photo thumbnail service by globo.com. Prior to 7.8.0, Thumbor’s HMAC validation can be bypassed due to the use of Python’s .replace() when removing the signature from the URL before validation. Since .replace() removes all occurrences of the substring, an attacker can insert the same signature multiple times in the URL and manipulate the final URL used for validation. This allows crafting URLs where the validated string differs from the actual requested resource, enabling loading images from unintended domains or paths. This issue is fixed in 7.8.0.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | thumbor Debian 14 | 7.8.0-1 | [DEBIAN-CVE-2026-53501](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53501.md) | Aug 1, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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